Rick Mendenhall of Albuquerque, N.M., throws a snowball during a snowball fight with friends on the National Mall in Washington, D.C. Thousands of flights were canceled, students got an extra day off from school, and the federal government closed its offices in the Washington area Tuesday.

Bashon Mann and his children sled down a hill at the Capitol as snow falls in Washington, D.C. Students and government workers were told to stay home while the winter weather hits the Mid-Atlantic region.

Trucks with snowplows line up on a ramp near Interstate 95, as motorists make their way around in Weston, Mass. Heavy snow has been forecast and a blizzard warning was posted for portions of Massachusetts, prompting Gov. Deval Patrick to dismiss nonemergency state workers early.

Here we go again. Earlier this month in St. Louis, Jerome Harris bundled up against frigid temperatures. Now, cold air is again rushing south from the Arctic and a "bomb" of a storm is brewing across much of the Eastern half of the nation.

Jeff Roberson
/ AP

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Originally published on January 21, 2014 3:54 pm

Just as we're getting used to hearing about the polar vortex, there's another cool-sounding weather term being thrown around that we've had to look up:

Well, as Bolaris says, it's a "rapidly intensifying storm." The conditions that set one off: According to WeatherPrediction.com, "bombogenesis typically occurs between a cold continental air mass and warm ocean waters or between a cold polar air mass and a much warmer air mass."

Those air masses mix together to form an "extratropical surface cyclone" — or, as in this case, a "bomb" of a storm.

Cyclones, as we've said, are "rotating storms spawned in the tropics." An "extratropical cyclone," though, has cold air at its core and can form over land or water, as The Weather Underground says. Bombogenesis also draws its name from another weather term — cyclogenesis — which is basically a fancy word for a cyclone's origin.

This bombogenesis blather comes, of course, because of what's expected to happen today from the Mid-Atlantic up into New England. There's going to be "moderate to locally heavy snow from the central Appalachians to southern New England, including all of the Mid-Atlantic region," the National Weather Service says. The storm — and the "bomb" — are being fueled by another blast of cold air from the North that's running into warmer air coming up from the South.

The forecast for 5 inches or more of snow today in the Washington, D.C., area has led to the shutdown of federal offices in the nation's capital. Schools are closed in cities and towns across the affected areas.

As The Weather Channel adds, the wicked weather will be affecting tens of millions of people in one of the nation's most-populated stretches.

Update at 8:45 p.m. ET: Cancellations Top 3,000

According to the FlightAware tracking site, a total of 3,011 flights were canceled inside the U.S. today, with more than 200 each originating at the Philadelphia, New York's LaGuardia, and Newark airports (the site also lists cancellations by destination airport).

Our original post continues:

Let us know how you fare as this bombogenesis blows through. And let us know if there are other weather terms you think are particularly interesting.